Modified Japanese Orthopaedic Association Score Research Articles

Postoperative Magnetic Resonance Imaging Can Predict Neurological Recovery After Surgery for Cervical Spondylotic Myelopathy: A Prospective Study With Blinded Assessments

Factors that can predict the recovery of cervical spondylotic myelopathy (CSM) patients postoperatively are of significant interest to physicians and patients and their families. Magnetic resonance imaging (MRI) scans are a common method of examination after surgery, and thus of interest as a predictor of outcome. To investigate whether findings on MRI at 6 months postoperatively could predict recovery at 1 year in CSM patients. In 52 consecutive prospective patients, MRI was performed preoperatively and 6 months postoperatively. T1 and T2 signal change (area, height, and segmentation) and spinal cord re-expansion were measured. Outcome measures evaluated at 1 year postoperatively were compared with preoperative values. Univariate and stepwise multiple regressions were undertaken. Using univariate analysis, patients whose cord failed to re-expand had poorer outcome according to the modified Japanese Orthopedic Association score and Nurick score (P = .014) and grip test (P = .006) postoperatively. Stepwise multivariate regression showed lack of cord re-expansion to be predictive of prognosis postoperatively in the modified Japanese Orthopedic Association score (P = .013) and Berg Balance Scale (P = .014), and walking test (P = .011). Postoperative hyperintense T2 signal change was predictive of worse outcome on the Berg Balance Scale (P = .014) and walking test (P = .020), Nurick score (P = .001), and Short Form-36 scores (P = .020). In cases in which the T2 signal intensified, there was a poorer outcome on Nurick scores (P = .013), grip test (P = .017), and Short Form-36 scores (P = .030). Findings on postoperative MRI at 6 months is of predictive value in determining outcomes in CSM patients. The persistence and type of T2 signal change and lack of re-expansion of the cord correlate with poorer recovery and likely reflect irreversible structural changes in the spinal cord.

Anterior cervical multilevel decompression and fusion using fibular strut as revision surgery for failed cervical laminoplasty

Retrospective analyses of six cases. To describe six patients with previous failed laminoplasty who were subsequently managed by anterior cervical decompression and fusion (ACDF) using fibular strut as revision surgeries. While several complications and unsatisfactory results of cervical laminoplasty have been reported, there is no general consensus on how to best surgically treat these pathological conditions. Six patients, who had been treated by laminoplasty for cervical spondylotic myelopathy (n = 2) or ossification of posterior longitudinal ligament (OPLL, n = 4) and had unfavorable outcomes, underwent ACDF using autogenous fibular strut grafts. The pathological factors associated with the poor outcomes were intraforaminal spur, slip, spondylotic change, disc herniation, and increase of OPLL in size. Clinical outcomes were assessed by evaluating the modified Japanese Orthopedic Association score (JOA score) of cervical myelopathy, severity of radicular pains, axial pains, and perioperative complications. In addition, C2-7 angle and the presence of bony union were analyzed. The revision ACDF significantly increased the mean ± SD. JOA score, from 10.3 ± 3.9 to 13.5 ± 2.7 points (p = 0.028), with a recovery rate of 47.1 ± 26.7%. Radicular pain and axial pain also improved. C2-7 angle was not changed significantly. Solid fusion was achieved in all patients at 12.2 ± 4.2 months after revision surgery. ACDF with fibular strut graft was effective as a revision procedure for failed laminoplasty.

Open-door laminoplasty for the treatment of failed anterior cervical spine surgery

To evaluate the outcome of open-door laminoplasty for the treatment of failed anterior cervical spine surgery. From February 2003 to June 2009, 15 patients underwent open-door laminoplasty for the failed anterior cervical spine surgery. The causes of revision and the progression of disease were analyzed. Japanese Orthopedic Association (JOA) scores and Nurick grade were adopted to record the improvement of neurological status and walking ability. Two patients were excluded for analysis because of lost follow-up and follow-up less than 12 months. The mean follow-up period after revision surgery for the other 13 patients was 26 months (ranged 13-52 months). The mean interval between the initial and revision surgery was 24 months (ranged 5 months to 6 years). The causes of revision were as following: degeneration of the adjacent segment in 2 cases, inadequate decompression in 5 cases, mis-diagnosis of ossification of posterior longitudinal ligament (OPLL) as myelopathy in 4 cases, and progression of OPLL in 2 cases. Posterior laminoplasty was recommended for each patient. After the operation, 13 patients improved neurologically with respect to JOA score, 12 patients improved their walking ability while 1 remained unchanged. The mean modified JOA scores improved from 10.5 to 13.8 (P<0.05), the average recovery rate was 53.0% after the revision operation. The mean overall Nurick grade was 3.1 preoperatively and 1.9 at the final follow-up (P<0.05), the mean improvement of the Nurick grade was 1.2. Complications included cerebrospinal fluid leakage in 1 case, new axial neck pain in 1 case, and transient C5 nerve root palsy in 1 case. Open-door laminoplasty is a straightforward and effective treatment for failed anterior cervical spine surgery due to inadequate decompression, progressive OPLL or degeneration of the adjacent segment. The merit of the open-door laminoplasty for failed anterior spine fusion is able to avoid high risk from initial anterior cervical spine surgery.

Validation of a Translated Version of the Modified Japanese Orthopaedic Association Score to Assess Outcomes in Cervical Spondylotic Myelopathy

Although the Japanese Orthopaedic Association (JOA) originally developed in Japan, the modified English version (mJOA) has become widely used and is arguably now the accepted standard. In order to apply the mJOA successfully at an international level, we have translated it with a validated approach into Dutch to pave the way for other translated versions. After a thorough forward and backward translation procedure, a final Dutch version of the mJOA was developed. This translated version was used to assess the interobserver reliability among 2 independent examiners by using a cohort of patients with neurological impairment due to spinal pathology. The mJOA grading scale was used by 2 independent examiners in 25 patients with a variety of spinal diseases. Initially, the interobserver reliability expressed as kappa was 0.56 +/- 0.11. Then, instructions were given to the instructors to refrain from providing patients with an interpretation of the symptoms. Patients were asked to restrict themselves to the questionnaire and select the most appropriate score without bias from the examiner. Kappa increased to 0.78 +/- 0.05. This difference reached statistical significance (P < .001). We present a streamlined approach to translate the mJOA into a language other than English. The approach resulted in a Dutch version of the mJOA that had a high degree of interobserver reliability.

Laminoplasty after Anterior Spinal Fusion for Cervical Spondylotic Myelopathy

To review outcomes of laminoplasty after anterior spinal fusion (ASF) in 8 patients with cervical spondylotic myelopathy (CSM). Records of 3 men and 5 women aged 49 to 80 (mean, 60) years who underwent laminoplasty after ASF for CSM were reviewed. Before and after ASF and laminoplasty, the causes of CSM, mechanical instability, the Pavlov Torg ratio, the numbers of levels of stenosis, myelomalacia, ASF, and laminoplasty, the modified Japanese Orthopaedic Association (JOA) score, and the Hirabayashi recovery rate were recorded in all the patients. After ASF, the mean modified JOA score improved to 9.6 from 8.3 (p=0.05), with a mean Hirabayashi recovery rate of 12.5% at the 12-month follow-up. However, it deteriorated to 9 after a mean of 25 (range, 3-54) months follow-up. Indications for a secondary laminoplasty included inadequate decompression (n=5), progression of prolapsed discs (n=4), osteophytes (n=3), ossification of the posterior longitudinal ligament (n=1), and hypertrophy of the ligamentum flavum (n=4). The mean interval between ASF and laminoplasty was 30 (range, 14-55) months. The mean number of levels of laminoplasty was 4.5 (range, 4-5). After laminoplasty, all patients had adequate spinal decompression with no cord compromise, neck pain or stiffness, despite the signal change remaining the same. Two patients improved, 2 deteriorated, and 4 remained unchanged with respect to walking status. The mean modified JOA scores improved to 9.7 from 9 (p=0.38); the mean Hirabayashi recovery rate was -1.5%. All patients had persistent myelomalacia, which was not reflected in the improved modified JOA score. Initial surgery (such as ASF) is more effective in relieving cord compromise and myelopathy. Inadequate decompression and progression of disease may necessitate secondary laminoplasty, which conferred additional benefits that 5 of our 8 patients enjoyed despite persistence of myelomalacia.

Compensatory cerebral adaptations before and evolving changes after surgical decompression in cervical spondylotic myelopathy

The goal of this study was to compare cortical sensorimotor adaptations associated with neurological deterioration and then recovery following surgical decompression for cervical spondylotic myelopathy (CSM). Eight patients with CSM underwent functional MR (fMR) imaging during wrist extension and the 3-finger pinch task, along with behavioral assessments before and 3 and 6 months after surgery. Six healthy control volunteers were scanned twice. Cervical spine MR imaging demonstrated successful cord decompression. The patients improved after surgery on the modified Japanese Orthopaedic Association score for the upper extremity, which correlated with the changes in task-associated activation in specific sensorimotor regions of interest. Pinch-related activation in sensorimotor cortex contralateral to the movement paradigm was reduced before surgery then increased toward the extent of healthy controls after surgery. Before surgery, patients showed broader activation in ipsilateral sensorimotor cortex during wrist extension than during pinch, but activations became similar to those of healthy controls after surgery. Pinch-related activation volume in the ipsilateral sensorimotor cortex and the magnitude of activation in the contralateral dorsal premotor cortex evolved linearly across time after surgery, along with wrist extension-related activation magnitude in the contralateral supplementary motor area. Serial fMR imaging studies in CSM can capture the adaptations in specific sensorimotor cortices that accompany clinical deterioration and postsurgical improvement in sensorimotor function associated with damage and partial recovery of conduction in corticospinal pathways. These adaptive regions can be monitored by serial fMR imaging to detect a critical loss of supraspinal reserve in compensatory plasticity, which might augment clinical information about the need for surgical decompression.

Post-Laminectomy Kyphosis in Patients with Cervical Ossification of the Posterior Longitudinal Ligament : Does It Cause Neurological Deterioration?

Total laminectomy (TL) is an effective surgical technique for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) along multiple levels. However, kyphosis and probable neurological deterioration have been frequently reported after laminectomy. We analyzed the changes in the cervical curvature after TL and subsequent changes in neurological status. We retrospectively reviewed the records of 14 patients who underwent TL for the treatment of cervical OPLL between Jan. 1998 and Dec. 2003. TL was selected according to the previously determined criteria. The curvature of the cervical spine was visualized on a lateral cervical spine X-ray and measured using Ishihara's Curvature Index (CI) before the operation and at the last follow-up examination. Perioperative neurological status was estimated using the modified Japanese Orthopedic Association score and the Improvement Rate (IR) at the same time as the images were evaluated. The mean age of the patients was 57 years, the male/female ratio was 10:4, and the mean follow-up period was 41 months. The mean number of OPLL was 4.9, and the mean number of operated levels was also 4.9. The CI decreased after TL (p=0.002), which was indicative of a kyphotic change. However, this kyphotic change showed no correlation with the length of the follow-up period, number of operated levels and preoperative CI. Neurological examination at the last follow-up showed an improved neurological status in all patients (p=0.001). There was no neurological deterioration in any case during the follow-up period. Moreover, there was no correlation between IR and the degree of kyphotic change. Postoperative complications, such as C5 radiculopathy and epidural bleeding, resolved spontaneously without neurological sequelae. Kyphotic change was observed in all but one patient who underwent TL for the treatment of cervical OPLL. However, we did not find any contributing factors to kyphosis or evidence of postoperative neurological deterioration.

Alternating cervical laminoplasty for cervical spondylotic myelopathy

We present a novel method of performing an 'open-door' cervical laminoplasty. The complete laminotomy is sited on alternate sides at successive levels, thereby allowing the posterior arch to be elevated to alternate sides. Foraminotomies can be carried out on either side to relieve root compression. The midline structures are preserved. We undertook this procedure in 23 elderly patients with a spondylotic myelopathy. Each was assessed clinically and radiologically before and after their operation. Follow-up was for a minimum of three years (mean 4.5 years; 3 to 7). Using the modified Japanese Orthopaedic Association scoring system, the mean pre-operative score was 8.1 (6 to 10), which improved post-operatively to a mean of 12.7 (11 to 14). The mean percentage improvement was 61% (50% to 85.7%) after three years. The canal/vertebral body ratio improved from a mean of 0.65 (0.33 to 0.73) pre-operatively to 0.94 (0.5 to 1.07) postoperatively. Alternating cervical laminoplasty can be performed safely in elderly patients with minimal morbidity and good results.

Commentary

Laminoplasty aims to decompress the spinal cord and stabilize the cervical spine in patients with multilevel cervical lesions. Not every patient with cervical compressive myelopathy is a good candidate for laminoplasty. Most studies recommend that neutral or kyphotic alignments are contraindications for laminoplasty. However, cervical sagittal alignment does not have a strong and consistent effect on the clinical outcomes of laminoplasty. Moreover, many reports on the effect of cervical sagittal alignment did not designate the ideal definition of alignment and used different definitions of lordosis.To identify the effect of preoperative cervical alignment according to two different definitions after midline splitting double-door laminoplasty.Retrospective cohort study.From August 2008 to September 2010, 58 patients were diagnosed with cervical myelopathy and treated with midline splitting double-door laminoplasty.The clinical results were assessed with the modified Japanese Orthopedic Association (JOA) score, neck disability index (NDI), and visual analog scale (VAS) and were compared to analyze the rate of change between preoperative and postoperative values. Postoperative radiological results at the final follow-up examinations were compared between groups to obtain the change in range of motion and sagittal alignment.The effect of cervical alignment on JOA, NDI, and VAS scales and also on change of alignment and change of range of motion (ROM) at the final follow-up examinations was analyzed statistically between two groups according to two different definitions such as Toyama classification and Cobb angle.No difference was found between the two groups according to Toyama classification in terms of the postoperative improvement rate of the modified JOA score (p=.086), decreasing rate of the VAS (p=.940) or NDI (p=.211), postoperatively. Additionally, no difference was found for the decreasing rate of ROM (p=.427) or sagittal alignment (p=.864) based on the radiological evaluation results. Also, there was no difference between two groups according to Cobb angle in terms of the modified JOA score (p=.743), VAS (p=.548), or NDI (p=.32), postoperatively. Additionally, no difference was found for the ROM (p=1.000) or sagittal alignment (p=.440) based on the radiological evaluation results.Despite nonlordosis cervical sagittal alignment, double-door laminoplasty would be effective for patients with cervical myelopathy because of cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament. Furthermore, sagittal alignment is not the absolute and sole factor that surgeons should consider when determining the optimal treatment strategy.

Surgical experience with symptomatic thoracic ossification of the ligamentum flavum

Symptomatic thoracic ossification of the ligamentum flavum (OLF) is rare, and its prognostic factors remain unclear. The authors retrospectively studied 24 patients with surgically treated thoracic OLF to delineate its prognostic factor. The clinical manifestations, radiological studies, surgical records, and pathological findings were reviewed. Preoperative and postoperative neurological data were reappraised using the American Spinal Injury Association and modified Japanese Orthopaedic Association (JOA) scoring systems. Spearman rank-correlation coefficients and nonparametric tests were used to analyze the correlations between the variables of patient characteristics, preoperative duration of symptoms, preoperative neurological status, associated spinal disorder(s) other than thoracic OLF, and the final functional outcome. Decompressive surgery is indicated in patients in whom symptomatic thoracic spinal cord compression is caused by intruding OLF. Magnetic resonance imaging can provide sufficient clues for the diagnosis of thoracic OLF. Higher preoperative modified JOA scores of 3 and 4 are positively correlated with better postoperatiVe functional recovery than lower scores. Surgery should be performed as soon as possible before independent ambulatory function is impaired.